The use of carrier matrices to promote the formation of bone at a site in a patient is well known, and related products are currently available on the market, such as MASTERGRAFT® Matrix, by Medtronic Sofamor Danek (Memphis, Tenn.). These matrices are typically in the form of a relatively large, soft collagen sponge. Before insertion into the target site, the sponge is wetted, usually with bone marrow aspirated from the patient, at a ratio of about 1:1 by volume. The bone marrow is permitted to soak into the scaffolding provided by the sponge, and the sponge is then kneaded by hand, thereby obtaining a pliable consistency that may subsequently be gently packed into the target site. The collagen in the sponge provides a malleable, non-water soluble carrier that permits accurate placement and retention of biological factors at the implantation site.
Because the sponge must be hand-packed, the surgeon is required to make an incision in the patient to reach the surrounding bone at the target site. The entire process is thus relatively invasive and painful. It would be beneficial if less intrusive means were available to deliver a collagen-based carrier matrix into a target space.